CenterVertexCount
The vertices whose greatest distance to another vertex is the least.
✓ checked against that system · ! checked, with disagreements (hover a chip)FindStat
St001342via LabeledGraph✓CenterVertexCount(graph)The vertices whose greatest distance to another vertex is the least.Typed signatures
| Type | Package | Applies |
|---|---|---|
(labeled_graph) -> number | combinatorics | always |
Details
- Defined over
LabeledGraphas an expression in_x, evaluated by compute-engine — the definition IS the implementation. - Takes a
LabeledGraphand nothing else — it reads values against their positions, or walks the orbits, so it needs the bijection. Applying it to a bare list is a type error, not a wrong answer. - FindStat's St001342. In a disconnected graph every vertex is as far as 2n from another, so all are central. The graph with no vertices gives 0.
Definition
Epsil, as the implementation runs it.
on LabeledGraph, over _x
0 if _x[1] == 0 else Apply((n: integer) => Apply((edges: list<list<integer>>) => Apply(
(adjacency: list<list<integer>>) => Apply(
(distances: list<list<integer>>) => Apply(
(eccentricity: list<integer>) => Max(Sum(Map(Function(1 if c == Min(eccentricity) else 0, c), eccentricity)), 0),
Map(Function(Max(distances[u]), u), Range(1, n)),
),
Apply((matrix: list<list<integer>>) => Apply(
(a_init: list<list<integer>>) => Fold((a: list<list<integer>>, k) => Apply(
(a_next: list<list<integer>>) => a_next,
Map(Function(Map(Function(Min(a[i][j], a[i][k] + a[k][j]), j), Range(1, n)), i), Range(1, n)),
), a_init, Range(1, n)),
Map(
Function(Map(Function(0 if i == j else 1 if matrix[i][j] == 1 else 2n, j), Range(1, n)), i),
Range(1, n),
),
), adjacency),
),
Map(Function(Map(
Function(Max(Sum(Map(Function((1 if e[1] == i else 0) *
(1 if e[2] == j else 0) +
(1 if e[1] == j else 0) *
(1 if e[2] == i else 0), e), edges)), 0), j),
Range(1, n),
), i), Range(1, n)),
), _x[2]), _x[1])Examples
Properties #
About
| Examples | 4 |
|---|---|
| Crosswalk | FindStat |